The Newtown, Conn., shooting has prompted a handful of states to enact tougher gun laws, and blue-state governors have led the way.

With Congress yet to agree on any federal changes, Maryland Gov. Martin O'Malley and New York Gov. Andrew Cuomo -- both thought to be Democratic presidential contenders in 2016 -- have shepherded tighter restrictions in their states. In Connecticut, Democratic Gov. Dan Malloy signed a new gun law earlier this month.

Add Chris Christie to that list.

On Friday, the New Jersey Republican governor and possible GOP White House hopeful unveiled a new plan for tighter gun laws in the Garden State.

Previously on the record as supporting some gun restrictions on the books in New Jersey -- some of the toughest in the nation -- the governor took an active turn on the gun issue. Christie proposed requiring mental-health adjudication records be added to background checks, banning the Barrett .50 caliber rifle, new and stiffer penalties for straw-purchasers and gun trafficking, parental consent for violent video game sales, and making it easier for doctors to mandate commitment or outpatient treatment for mental-health patients deemed dangerous. He added a mental-health working group to a state gun-violence task force, charged with making recommendations.

"The existing system that we have placed in New Jersey is much stronger already than the proposed Toomey-Manchin legislation that failed in the Senate earlier this week," Christie said at a news conference on Friday. "The [state] assembly has put some bills forward, the [state] senate's gonna put some bills forward, I've now put bills forward, and now we have to let the process work to reach consensus of what works for the people of the state."

Highlighting a political conundrum for Christie, the gun push will likely play well in his home state, which already restricts guns more aggressively than most -- but it might raise concerns among Republicans elsewhere, posing a hurdle for Christie if he seeks the presidency in 2016.

"He may come right at it and try to stare people down by sheer force of his personality and attempt to convince people that he's one of them in spite of these steps," Appell said. "He will find, as many have before him, that it won't play. It'll slam him right back in the face."

In his new push, Christie has bucked conservative orthodoxy for the second time this year. In February, he joined seven other Republican governors in accepting an expansion of state Medicaid programs under President Obama's health-reform law, the Affordable Care Act.

"It is clear over the past two or three months that he really worked to prioritize his New Jersey constituency over his national conservative constituency, and this is kind of groundbreaking, because up until about two or three months ago, we saw a series of actions that really defied public opinions in the state," said Prof. Brigid Harrison, who teaches political science and law at Montclair State University in Montclair, N.J.

Harrison referenced Christie's cuts to family-planning funding in the state budget.

Christie already has some problems with conservative activists. After supporting a federal Hurricane Sandy relief bill, he was not invited to the Conservative Political Action Conference, an annual confab that hosts top conservative politicians for speeches to a large crowd of activists in the Washington, D.C., area.

But he also faces a race against Democratic State Sen. Barbara Buono this year, and Democrats will eye that race as an opportunity to ding him before any presidential ambitions percolate further.

Christie's package of gun reforms might not sit well with conservatives, but it might not be the most controversial group of measures, either. Since the Newtown, Conn., school shooting, Republicans have raised the idea of requiring mental-health records to be added to the National Instant Criminal Background Check System (NICS), which the FBI uses to screen gun purchasers. While a bill to increase penalties on "straw-purchasers" passed the Senate Judiciary Committee with only one GOP vote, Utah GOP Sen. Orrin Hatch praised the idea of getting tougher on straw-purchasers, even as he voted against the measure for casting "too wide a net."

The outright banning of the Barrett .50 caliber rifle, meanwhile, runs directly counter to GOP politicians' staunch opposition to banning "assault weapons." While gun-control measures like expanded background checks have garnered wide support across party lines, banning "assault weapons" has not. In an April 4 poll by Quinnipiac University, 55 percent of Republicans said they opposed that policy.

New Jersey already bans some "assault weapons" and large-capacity magazines. In 2001, the latest year in which the Brady Campaign to Reduce Gun Violence scored states' gun restrictions, New Jersey ranked second only to California in having the tightest controls on the books.

Politically, Christie may have taken control of some criticism he was bound to receive anyway. As a former U.S. attorney running for governor in 2009, Christie voiced support for some of New Jersey's gun laws, suggesting fewer guns are better -- something conservative critics could easily raise, regardless of his current push for new laws, should he ever run for president.

"At the end of the day, what I support are common-sense laws that will allow people to protect themselves," Christie told Fox News's Sean Hannity in an October 2009 interview, days before he defeated Democratic incumbent Gov. Jon Corzine. "But I also am very concerned about the safety of our police officers on the streets. Very concerned. And I want to make sure that we don't have an abundance of guns out there."

Taking an active approach to gun control could be considered a low-cost move, Monmouth University polling director Patrick Murray suggested.

"Voters in New Jersey don't see this as a major issue that needed to be addressed in the state, but it helps him to address the charges that he's out of step on some of the social issues, namely gay marriage and abortion," Murray said.

"The calculation that he made here is that in the wake of the Newtown tragedy, he had to do something. In New Jersey, there wasn't a requirement to do much of anything" because of the state's already-stringent gun laws, Murray said. "Those that were going to go after him on his gun stances were going to do that anyway."